Process for producing epoxidized organic polymer, thermoplastic resin composition, primer composition, unvulcanized rubber composition, rubber moldings, and process for producing the molding

ABSTRACT

A process for preparing an epoxidized organic polymer by dispersing or suspending a solid organic polymer in an organic solvent and epoxidizing the dispersed or suspended polymer with a peroxide. The epoxidized polymer thus obtained is usable for coating materials, resin modifiers, rubber modifiers or adhesives, thus being extremely useful. The epoxidized organic polymer is useful to prepare a thermoplastic resin composition having improved mechanical strength, and comprising a thermoplastic resin, an epoxidized EPDM and an acid anhydride. The thermoplastic composition can be used to prepare a primer composition including a 100 parts by weight of an epoxidized EPDM and 50 to 70 parts by weight of a product of chlorination of a polyolefin modified with an unsaturated carboxylic acid or an anhydride thereof. An unvulcanized rubber composition can be prepared for the epoxidized EPDM, a diene polymer and a vulcanizing agent, and the unvulcanized rubber composition can be used in a process for producing rubber moldings by extruding the unvulcanized rubber composition and vulcanizing the extrudate.

TECHNICAL FIELD

The present invention relates to a process for producing an epoxidizedorganic polymer which may be used for the preparation of paints, resinmodifiers, rubber modifiers, adhesives, etc. More particularly, theinvention relates to a process for producing an epoxidized organicpolymer in which carbon-carbon double bonds (hereinafter referred tosimply as "double bonds") present in the molecular chain of the organicpolymer are oxidized with the organic polymer in a dispersed orsuspended state in a solvent, to thereby simplify post-treatment.

The present invention also relates to use of an epoxidized organicpolymer, an epoxidized ethylenepropylene dieneterpolymer (hereinafterethylenepropylene dieneterpolymer is referred to as EPDM), which useincludes thermoplastic resin compositions having improved mechanicalstrength which are obtained by incorporating epoxidized EPDM and acidanhydrides into a variety of thermoplastic resins and heating theresultant mixture, as well as to primer compositions formed of EPDM,more particularly, primer compositions which are endowed with excellentadhesion to both top coats and polyolefin moldings such as polypropylenebumpers and with excellent paint storage stability.

The present invention also relates to an unvulcanized rubber compositionwhich is formed of an epoxidized EPDM and a diene polymer and is endowedwith excellent coating ability, to rubber moldings formed of thecomposition, and to a process for producing the moldings.

BACKGROUND ART

Hitherto, there have been known the following processes for thetransformation of an organic polymer into an epoxidized organic polymerthrough oxidation: (1) a process in which percarboxylic acid is preparedin advance by reacting hydrogen peroxide with a lower carboxylic acidsuch as formic acid or acetic acid, and the percarboxylic acid is addedto the reaction system as an epoxidizing agent so as to cause anepoxidizing reaction in the presence or absence of a solvent, and (2) aprocess in which epoxidizing reaction is caused by use of hydrogenperoxide in the presence of a catalyst such as an osmate or tungsticacid, and a solvent. These processes are both characterized in that anorganic polymer to be epoxidized is dissolved in a solvent so as tocarry out epoxidized reaction effectively, and the synthesizedepoxidized organic polymer is recovered by desolvating treatment.

According to these processes, if the organic polymer to be epoxidized isin a liquid state or paste state, the resultant epoxidized organicpolymer is also in a liquid or paste state, and therefore, the lattercan be readily recovered by a desolvating procedure. However, if in asolid state, the reaction mixture is subjected to a desolvatingprocedure to cause the epoxidized organic polymer to precipitate in asolid state, and this precipitation and recovering operation for theepoxidized product is very difficult. Particularly when the organicpolymer to be epoxidized is a rubber polymer, the synthesized epoxidizedorganic polymer becomes viscous to considerably reduce workability.

Under the above circumstances, a process for producing epoxidizedorganic polymers which involves a simplified post-treatment is desired.

In the meantime, Japanese Patent Application Laid-Open (kokai) No.60-168750 discloses a thermoplastic polyester which contains epoxidizedEPDM as an agent to improve impact resistance. Yet, improvement ofimpact resistance of general thermoplastic resins, includingthermoplastic polyesters, is still desired.

Conventional primers for polypropylene are described, for example, inJapanese Patent Publication (kokoku) No. 63-54312, which disclosesprimers obtained through graft-polymerization of maleic anhydride to achlorinated polypropylene resin; and in Japanese Patent Publication(kokoku) No. 62-21027, which discloses primers obtained throughgraft-polymerization of maleic anhydride to a polypropylene/ethylenecopolymer. Moreover, Japanese Patent Application Laid-Open (kokai) No.4-258643 discloses primers having improved adhesion, which is attainedby co-use of a chlorinated polypropylene resin and any one of a sorbitolepoxy resin, glycol-ether-type epoxy resin, or a bisphenol epoxy resin.In addition, Japanese Patent Application Laid-Open (kokai) No. 7-150107discloses primers containing a butadiene epoxy resin in a graft polymerformed of chlorinated polypropylene and maleic anhydride.

However, of the above-mentioned primer compositions, those disclosed inJapanese Patent Publication (kokoku) Nos. 63-54312 and 62-21027 andJapanese Patent Application Laid-Open (kokai) No. 4-258643 do notexhibit sufficient adhesive properties when they are tested forwaterproofness and antihygroscopic properties, unless they arepre-treated by cleaning with trichloroethane vapor. The primercompositions disclosed in Japanese Patent Application Laid-Open (kokai)No. 7-150107 also has the same problem, if there remain mold releasingagents used at the time of molding. Such a case requires wiping with asolvent such as isopropyl alcohol or toluene or similar steps. Washingwith aqueous substances in turn requires a facility enabling manycleaning steps, such as so-called power-wash, which results inconsiderably high facility costs and cleaning costs.

Regarding techniques related to unvulcanized rubber compositions,Japanese Patent Application Laid-Open (kokai) No. 3-161329 discloses aprocess for producing a rubber composition suitable for weather strips.The technique disclosed in that publication is characterized by thefollowing. An adhesive layer of a nitrile rubber/EPDM blend is formed onthe glass portion of the main body of glassrun made of EPDM. Uponformation of the adhesive layer, an extruder that extrudes a glassrunmain body and another extruder that extrudes an adhesive layer areconnected to a multi-color extrusion head, to thereby effectco-extrusion. Subsequently, the adhesive layer on the glass portion ofthe glassrun main body of the thus-extruded molding is coated with aurethane paint by way of a conventional method such as flow coating orbrushing, and then vulcanized.

However, since the process disclosed in that publication employsindependent extruders for performing extrusion of the glass portion ofthe glassrun main body and extrusion of the adhesive layer, facilitycosts rise. Moreover, since a urethane paint is required to be appliedthrough a customary method onto the extrudate that has left the extruderand not yet been vulcanized, the coating means cannot contact theglassrun main body, and therefore, particularly in the case in which themolded product has a cross section that is difficult to unfold, thereexist portions that cannot be easily coated. Independently, JapanesePatent Application Laid-Open (kokai) No. 5-237448 discloses a techniquefor improving coating properties by the incorporation of EPDM andpolyglycidyl methacrylate into a rubber composition. However, there isdesired development of a technique that uses fewer ingredients,eliminates use of polyglycidyl methacrylate, and still providesexcellently improved coating properties.

DISCLOSURE OF THE INVENTION

The present inventors have found that when an epoxidizing agent isapplied to a solid organic polymer which has been dispersed or suspendedin an organic solvent, the polymer is epoxidized satisfactorily, andepoxidized organic polymer can be obtained with a simplifiedpost-treatment. The present invention was accomplished based on thisfinding.

Moreover, the inventors have found that a thermoplastic compositionhaving improved strength can be obtained by incorporating into athermoplastic resin an epoxidized EPDM which is an epoxidized organicpolymer and an organic compound having a functional group that reactswith an epoxy group, such as an acid anhydride, and heating theresultant material. The present invention was accomplished based also onthis finding.

Moreover, the inventors have found that a primer composition containingan epoxidized EPDM which is an epoxidized organic polymer which hasexcellent adhesion to polyolefin and a topcoat, excellent paint storagestability, and excellent adhesion even when a mold releasing agent iscontaminated. The present invention was accomplished based also on thisfinding.

In addition, the inventors have found that an unvulcanized rubbercomposition having excellent coating properties can be obtained in theabsence of polyglycidylmethacrylate, if an epoxidized EPDM and a dienepolymer are incorporated. The present invention was accomplished basedalso on this finding.

Accordingly, the present invention provides a process for preparing anepoxidized organic polymer, characterized by dispersing or suspending asolid organic polymer in an organic solvent and epoxidizing thedispersed or suspended polymer with a peroxide.

The present invention also provides a composition comprising anepoxidized EPDM which is an epoxidized organic polymer, an organiccompound that reacts with an epoxy group, such as an acid anhydride, anda thermoplastic resin.

The present invention also provides a primer composition characterizedby comprising 100 parts by weight of an epoxidized EPDM which is anepoxidized organic polymer and 50 to 70 parts by weight of achlorination product of a polyolefin modified with an unsaturatedcarboxylic acid or an anhydride thereof.

In addition, the present invention provides an unvulcanized rubbercomposition comprising an epoxidized EPDM, a diene polymer, and avulcanizing agent. Still additionally, the present invention provides aprocess for producing rubber moldings, characterized by extruding theunvulcanized rubber composition and subsequently vulcanizing theextrudate.

BEST MODES FOR CARRYING OUT THE INVENTION

Preparation of an Epoxidized Organic Polymer

According to the process of the present invention for the preparation ofthe epoxidized organic polymer, a solid resin or a solid rubber polymeris used as the solid organic polymer (hereinafter referred to as anorganic polymer to be epoxidized). The resin or rubber polymer is notparticularly limited so long as it has a double bond in the molecule.Thus, both homopolymers and copolymers of two or more monomers may beused. The process of the present invention is particularly useful whenthe organic polymer to be epoxidized is a rubber polymer.

Specific examples of homopolymers include polybutadiene (BR),polyisoprene rubber, polynorbornene (rubber), polybutylene, anddicyclopentadiene resins and cyclopentadiene resins which are polymersof alicyclic diene monomers.

Illustrative examples of monomers that constitute the above-mentionedcopolymers include vinyl aromatic hydrocarbons, diene compounds, olefincompounds, and other copolymerizable monomers.

Examples of vinyl aromatic hydrocarbons include styrene,alkyl-substituted styrenes such as alpha-methyl styrene,alkoxy-substituted styrenes, vinyl naphthalene, alkyl-substitutedvinylnaphthalenes, divinylbenzene, and vinyltoluene.

Examples of diene compounds include 1,3-butadiene, isoprene,1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, piperylene,3-butyl-1,3-octadiene, and phenyl-1,3-butadiene. Moreover, mention maybe given of those diene compounds having an alicyclic skeleton such asdicyclopentadiene, cyclopentadiene, and ethylidenenorbornene.

Examples of olefin compounds include ethylene and propylene.

Examples of other copolymerizable monomers include acrylonitrile.

The organic polymer to be epoxidized that is used in the presentinvention may be a copolymer of two or more copolymerizable monomersmentioned above. The copolymers may be either random or blockcopolymers.

In the present invention, when the copolymers are random copolymers,they are preferably EPDMs (ethylenepropylene dieneterpolymers). This isbecause EPDMs do not dissolve in a solvent such as an acetic ester orketone, thus allowing the solvent to penetrate inside the polymers foreffecting epoxidization.

The iodine value of EPDMs is preferably 5-100, particularly preferably10-50. Iodine values in excess of 100 result in poor compatibility withthermoplastic resins such as polyethylene and polypropylene, allowingthe crosslinking density to rise excessively, which may invitedeteriorated rubber elasticity. On the other hand, iodine values lessthan 5 cannot provide the effect of epoxidization.

When the copolymers are block copolymers, they are preferablypolystyrene-polybutadiene block copolymers,polystyrene-polybutadiene-polystyrene block copolymers (SBSs),polystyrene-polyisoprene-polystyrene block copolymers (SISs), orpolyacrylonitrile-polybutadiene block copolymers (NBRs). The molecularstructure of the block copolymers may be linear, branched, or radial. Nolimitation is imposed on the average molecular weight of the blockcopolymers; however, it is preferable to use block copolymers which havea low molecular weight and which do not dissolve in organic solvents.The terminal groups of the resins or rubber polymers serving as organicpolymers to be epoxidized are not particularly limited.

The present invention is characterized in that the organic polymer to beepoxidized is in a solid state in an organic solvent. The expression"solid state" encompasses powders, granules, and similar forms.

Commercially available pellets per se may be used as the organic polymerto be epoxidized. However, in order to perform epoxidization reactionefficiently, the pellets are preferably pulverized to increase thesurface area, with the particle diameter being as small as possible. Forexample, according to tests conducted by the present inventors, theepoxidization ratio (i.e., the percentage of epoxidized double bondswith respect to all double bonds) attained when pellet-shaped polymersare epoxidized was 20-50%, whereas when materials that had passedthrough a 4-mesh sieve or a 7.5-mesh sieve were epoxidized,epoxidization was 50-80% or 80-90%, respectively.

Pulverization may be performed through use of an ordinary mill. When theorganic polymer to be epoxidized is a rubber polymer, the polymer ispreferably pulverized by use of a freeze-pulverization method.

Epoxidization of the present invention is characterized in that anorganic solvent is used for the purpose of dispersing or suspending theorganic polymer to be epoxidized, and a peroxide is used as anepoxidizing agent to thereby epoxidize the organic polymer to beepoxidized directly in its own solid form.

The organic solvent should not dissolve the organic polymer to beepoxidized, or alternatively, the organic solvent should be used underreaction conditions in which the solubility of the organic polymer to beepoxidized is low. The reason is as follows: Generally speaking, when anorganic polymer to be epoxidized is solid at normal ambient temperatureand is dissolved in an organic solvent and epoxidized, the resultantepoxidized organic polymer that has been synthesized is to be recoveredby a desolvating procedure. However, during this desolvating procedure,epoxidized products precipitate, making collection operation from theorganic solvent difficult.

The organic solvent may be suitably selected in accordance with thespecies of the epoxidized organic polymer and reaction conditions ofepoxidization. Examples of the organic solvent include linear orbranched hydrocarbons such as hexane and octane, as well as theiralkyl-substituted derivatives; alicyclic hydrocarbons such ascyclohexane and cycloheptane, as well as their alkyl-substitutedderivatives; aromatic hydrocarbons such as benzene, naphthalene,toluene, and xylene, as well as alkyl-substituted aromatic hydrocarbons;aliphatic carboxylic esters such as methyl acetate and ethyl acetate;and halogenated hydrocarbons. Of these substances, preferred ones arecyclohexane, ethyl acetate, chloroform, toluene, xylene, hexane, etc. inconsideration of solubility of the epoxidized organic polymer and easeof subsequent collection of the organic solvent.

The amount of the organic solvent used in the epoxidizing reaction issuitably determined in accordance with the species of the organicpolymer to be epoxidized, the surface area, the species and amount ofthe catalyst which will be described hereunder, the epoxidizing reactionconditions, etc. Preferably, the amount of the organic solvent is in therange of one-half to five times on a weight basis, particularlypreferably an equal amount to three times, that of the organic polymerto be epoxidized. If the amount is smaller than one-half, the organicpolymer to be epoxidized cannot be sufficiently dispersed or suspended,whereas amounts greater than five times result in intricate desolvatingprocedure after completion of epoxidizing reaction and separation andrecovery of the products.

Examples of peroxides serving as an epoxidizing agent includepercarboxylic acids such as performic acid, peracetic acid, andperpropionic acid. These peroxides are preferably in their anhydrideforms. However, epoxidization may also be performed in a system thatuses peroxides containing H₂ O derived from hydrogen peroxide.

When percarboxylic acids are used as the epoxidizing agent, thepercarboxylic acids are preferably dissolved in a solvent before use.Examples of usable solvents include hydrocarbons such as hexane, organicacid esters such as ethyl acetate, and aromatic hydrocarbons such astoluene. Use of a solvent is recommended, because solvents permeateinside the organic polymer to be epoxidized and accelerate epoxidizingreaction. Solvents for percarboxylic acids may be identical to those fordispersing the organic polymer to be epoxidized.

In use of peroxides derived from hydrogen peroxide, percarboxylic acidis first prepared by reacting hydrogen peroxide and a lower carboxylicacid such as formic acid or acetic acid, and the resultant percarboxylicacid, serving as an epoxidizing agent, is added to the reaction systemso as to cause an epoxidizing reaction. Alternatively, epoxidizingreaction may be performed through use of hydrogen peroxide in thepresence of a catalyst such as an osmate or tungstic acid, and asolvent. In the present invention, either method may used. In thisconnection, solvents which are usable in the latter case may beidentical to those listed above as solvents for percarboxylic acids.

The oxygen concentration of oxirane of the epoxidized organic polymercan be controlled by varying the reaction molar ratio of the quantity ofdouble bonds contained in the organic polymer to be epoxidized to thequantity of epoxidizing agent. The reaction molar ratio is suitablydetermined in accordance with the oxirane oxygen concentration of thetarget organic polymer to be epoxidized. However, the reaction molarratio (a/b) of the quantity of double bonds contained in the organicpolymer to be epoxidized (a) to the amount of peroxides reduced to theamount of pure peroxides (b) is preferably in the range of 1.0-2.0,particularly preferably 1.1-1.8.

The reaction temperature of epoxidization reaction is suitablydetermined in accordance with the species of the organic polymer to beepoxidized, the surface area, the species of the solvent, the speciesand amount of the epoxidizing agent, and the reaction conditions.Preferably, the reaction temperature is 20-80° C., and particularlypreferably 30-60° C. Temperatures lower than 20° C. are not practical,as the reaction rate is slow. On the other hand, when the temperature ishigher than 80° C., self-decomposition of peroxides becomes significant,which is not preferable. Although the reaction pressure is normallyatmospheric pressure, slightly reduced or increased pressures may alsobe used.

The reaction time for epoxidization is suitably determined in accordancewith the species of the organic polymer to be epoxidized, the surfacearea, the species of the solvent, the species and amount of theepoxidizing agent, and the reaction temperature. Preferably, thereaction time is 1-5 hours. If the reaction time is shorter than onehour, the conversion rate of double bonds is excessively low and is notpreferable. On the other hand, if the reaction time is in excess of fivehours, considerable addition reaction occurs between the epoxidizedorganic polymer and acetic acid--in the case in which acetic acid isused as a peroxide--causing a reduced yield, which is disadvantageous.

After completion of epoxidization reaction, an epoxidized organicpolymer in a solid form exists in a dispersed or suspended state in anorganic solvent in which byproducts and carboxylic acid are dissolved.According to a characteristic feature of the present invention, theepoxidized organic polymer is recovered in a solid form.

As used herein, the expression "recover in a solid form" refers to theoperation in which an epoxidized organic polymer which has undergoneepoxidizing reaction and which is present in a dispersed or suspendedstate i.e., in a solid form in the reaction mixture is recovered withits solid form being maintained. Accordingly, this expression does notencompass the case in which an epoxidized organic polymer is dissolvedin a reaction mixture upon completion of epoxidization reaction andsubsequently a desolvating operation is performed to thereby cause thepolymer to precipitate in a solid form. In the present invention,epoxidizing reaction is performed while the solid state is maintained,and the resultant epoxidized organic polymer is also recovered in asolid state, to thereby produce epoxidized organic polymers withexcellent workability.

In order to recover solid matter, the suspension may for example besubjected to filtration or centrifugal separation to thereby separateand recover a solid epoxidized organic polymer. Final products may beobtained by washing the thus-separated and recovered solid epoxidizedorganic polymer with water so as to remove the solvent, carboxylic acid,etc., and drying the washed material under reduced or reduced pressure,and with or without heating.

In accordance with the process of the present invention for producingepoxidized organic polymers, there can be produced epoxidized EPDMs,epoxidized SBSs, epoxidized SISs, epoxidized NBRs, epoxidized SBRs,epoxidized BRs, epoxidized isoprene rubber, epoxidized butyl rubber,etc. These compounds may be used as paints, resin modifiers, rubbermodifiers, adhesives, resin compositions, etc.

Thermoplastic Resin Compositions

When the epoxidized EPDM obtained from the process of the presentinvention for epoxidized organic polymers--along with an organiccompound having a functional group that reacts with an epoxy group, suchas an acid anhydride--is incorporated into a thermoplastic resin andheat is applied, it is possible to obtain a thermoplastic resincomposition having improved mechanical strength.

No particular limitation is imposed on the identity of the thermoplasticresin serving as a constituent of the thermoplastic resin composition ofthe present invention. For example, mention made be given of compoundsthat are used as molding materials, including polyolefin, polyvinylchloride, polyvinylidne chloride, polyesters, polyamides,polycarbonates, polyvinyl acetate, polyacetal, polystyrene, ABS resins,methyl polymethacrylate, and fluorocarbon resins. Of these compounds,polyolefin is particularly preferred, and specific examples ofpolyolefin include homopolymers and copolymers of alpha-olefins such asethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-pentene, 1-hexene,4-methyl-1-pentene, 1-heptene, and 1-octene; and copolymers of one ofthese alpha-olefins and small amounts of other copolymerizable monomersincluding (meth)acrylic esters such as vinyl acetate, acrylic acid,methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate,and ethyl methacrylate. Polypropylene is particularly preferred.

Epoxidized EPDM which is incorporated into the thermoplastic resincomposition of the present invention preferably has an oxygenconcentration in oxirane of 0.1-2.0% by weight, particularly preferably0.11-1.75% by weight. If the concentration is lower than 0.1% by weight,effect of improving mechanical strength of the thermoplastic resinbecomes poor, whereas use of starting EPDMs that realize an oxygenconcentration in oxirane of more than 2.0% by weight is disadvantageous,as they are difficult to obtain. The ratios of copolymerization withethylene, propylene, and diene compounds that constitute EPDM are notparticularly limited. However, the ratios are preferably such that theiodine value falls within the range of 10-50.

The compounds having functional groups that react with epoxygroups--which compounds are used in the production of the thermoplasticresins of the present invention--have two or more functional groups.Alternatively, derivatives thereof may be used. Examples of suchcompounds include dicarboxylic acids, acid anhydrides, diamines, anddiphenols.

Examples of dicarboxylic acids include aromatic dicarboxylic acids suchas phthalic acid, isophthalic acid, terephthalic acid, andnaphthalenedicarboxylic acid; aliphatic dicarboxylic acids such asoxalic acid, succinic acid, malonic acid, adipic acid, sebacic acid, andundecadicarboxylic acid; and alicyclic dicarboxylic acids such astetrahydrophthalic acid.

Examples of acid anhydrides include maleic anhydrides, itaconicanhydrides, citraconic anhydrides, nadic anhydrides(endocis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid anhydrides),succinic anhydrides, phthalic anhydrides, tetrahydrophthalic anhydrides,hexahydrophthalic anhydrides, trimellitic anhydrides, head anhydrides(chlorine-containing derivatives of phthalic acid), himic anhydrides,methylhimich anhydrides (methylendomethylene tetrahydrophthalicanhydrides), adipic anhydrides, azelaic anhydrides, and sebacicanhydrides. Alicyclic acid anhydrides are particularly preferred.

Examples of diamines include stearylpropylene diamine,1,4-bis(3-aminopropylpiperazine), and p-phenylene diamine.

Examples of diphenols include bisphenol A and bisphenol F.

The proportions of the above-described three ingredients that constitutethe thermoplastic resin composition of the present invention arepreferably such that epoxidized EPDM is used in an amount of 10-60 partsby weight, more preferably 30-50 parts by weight, with respect to 100parts by weight of a thermoplastic resin, and that an acid anhydride isincorporated in an amount of 0.5-2 equivalent weights of the oxygenconcentration of oxirane of the epoxidized EPDM.

The thermoplastic resin composition of the present invention mayoptionally contain, in addition to the aforementioned three ingredients,reinforcing agents such as glass, mica, and clay; pigments; a variety ofstabilizers; antistatic agents; and nucleating agents.

The thermoplastic resin composition of the present invention is preparedby blending the above-described three ingredients with other additives,heating, and mixing. These steps are performed under stirringconditions. For this purpose, an extruder is usually used and theingredients are kneaded therein. The resultant thermoplastic resincomposition is obtained in the form of pellets. It is considered thatmechanical strength of the thermoplastic resin is improved throughheating and kneading, during which the functional groups possessed bythe ingredients react with one another. Accordingly, there may be addeda compound capable of serving as a catalyst, e.g., triphenylphosphine, aphosphoric ester, diazabicycloundecene (DBU), aluminum isopropoxide,etc.

Primer Compositions

Primer compositions may be obtained from the epoxidized EPDM prepared inaccordance with the process of the present invention for producingepoxidized organic polymers and a chlorination product of apolypropylene resin modified with one, two, or more members selectedfrom the group consisting of unsaturated carboxylic acids and theiranhydrides.

The epoxidized EPDM used in the preparation of a primer compositionpreferably has an oxygen concentration in oxirane of 0.1-2.0% by weight,particularly preferably 0.11-1.75% by weight. If the concentration isbelow 0.1% by weight, interlayer adhesion to a topcoat layer is notsufficient, whereas starting EPDMs that realize an oxygen concentrationin oxirane of more than 2.0% by weight are disadvantageous, as they arenot readily available. The ratios of copolymerization with ethylene,propylene, and diene compounds that constitute EPDM are not particularlylimited. However, the ratios are preferably such that an iodine valuefalls within the range of 10-50.

Chlorinated products of polyolefins that have been modified withunsaturated carboxylic acids or their anhydrides may be prepared throughthe process described hereunder.

Polyolefins that serve as starting materials of modified polyolefins,which have been modified with unsaturated carboxylic acids or theiranhydrides, include crystalline polypropylene, noncrystallinepolypropylene, polybutene-1, polypentene-1, poly4-methylpentene-1,low-density- or high-density-polyethylene, and ethylene/propylenecopolymers. Of these, crystalline polypropylene is preferred. Thepolyolefins, being used singly or in combination of two or more, aremade molten with heat, and if necessary, their viscosity is decreasedthrough a thermal decomposition process. To the resultant polyolefinresin is added unsaturated carboxylic acid or an anhydride thereof inthe presence of a radical generator, and subsequently, the additionproduct is dispersed or dissolved in a chlorinating solvent. Reaction isallowed to proceed in the presence of a catalyst or with irradiation ofUV rays, at a temperature of 50-120° C., under atmospheric pressure orpressurized conditions while chlorine gas is blown.

Examples of unsaturated carboxylic acids or their anhydrides used forperforming a modification reaction include maleic acid, maleicanhydrides, citraconic acid, citraconic anhydrides, fumaric acid,itaconic acid, and itaconic anhydrides. Of these, maleic anhydrides arepreferred.

Examples of radical generators used in the modification reactioninclude, but are not limited to, peroxides such as di-tert-butylperoxide, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide,and methylethylketone peroxide; and azonitriles such asazobisisobutylonitrile and azobisisopropionitrile.

The saponification value of chlorination products which can be used inthe present invention, i.e., chlorination products of polyolefin thathas been modified with an unsaturated carboxylic acid or an anhydridethereof is not less than 6, and preferably 10-60 (measuring method: JISK0070). If the saponification value is lower than 6, compatibility withother resins is poor, inviting the risk of separation during the storageof primer solutions, or reduction in luster. On the other hand, if thesaponification value is in excess of 60, adhesion with polyolefins suchas polypropylene resins becomes poor.

The amount of grafting of the unsaturated carboxylic acid or ananhydride thereof is in the range of 0.5-3.0% by weight. If the amountof grafting is less than 0.5% by weight, interlayer adhesion to atopcoat becomes insufficient, whereas amounts in excess of 3.0% byweight cause poor paint storage stability and are not preferred.

The chlorination degree of polyolefins that have been modified withunsaturated carboxylic acids or anhydrides thereof is preferably in therange of 10-50% by weight, particularly preferably 15-35% by weight.(Measurement method: Specifically, NaOH solution, which is achlorine-absorbable solution, is placed in a combustion flask, and theinterior of the flask is purged with oxygen. Subsequently, a sampleplaced in a platinum basket is ignited and burned in the flask. Aftercompletion of combustion, the absorption liquid is titrated with silvernitride, and the chlorination degree is computed.) If the chlorinationdegree is lower than 10% by weight, the solution condition deteriorates,whereas if the chlorination degree is in excess of 50% by weight,adhesion to polyolefins may become poor.

The amount of the chlorination product of a polyolefin that has beenmodified with unsaturated carboxylic acid or an anhydride thereof is inthe range of 50-70 parts by weight with respect to 100 parts by weightof epoxidized EPDM. If the amount of the chlorination product of apolyolefin that has been modified with unsaturated carboxylic acid or ananhydride thereof is less than 50 parts by weight, insufficient adhesionresults, whereas if the amount is in excess of 70 parts by weight, theamount of epoxidized EPDM becomes less than 30 parts by weight, causinginsufficient adhesion when the molded product to which the primer isapplied is contaminated with a mold-releasing agent.

The primer composition of the present invention can be obtained bymixing, in a suitable solvent, epoxidized EPDM and a chlorinationproduct of a polyolefin that has been modified with unsaturatedcarboxylic acid or an anhydride thereof. Solvents that may be used arepreferably the same solvents that were employed in the production of thechlorination product of a polyolefin that has been modified withunsaturated carboxylic acid or an anhydride thereof. Also, the primercomposition may contain 0-60 parts by weight of other resin componentswith respect to 100 parts by weight of a solid resin content exceptingthe solvent. Almost all types of resins generally used for thepreparation of paints, such as acrylic resins, polyester resins, andurethane resins, can be used as co-usable resins.

The primer compositions of the present invention exhibit excellentadhesion even when molded products are contaminated with amold-releasing agent. This effect is considered to be attributed to thechemical structure of epoxidized EPDM, which resembles that ofmold-releasing agents and polypropylene bumper materials: the epoxidizedEPDM comes to be compatible with the mold-releasing agent present on thesurface and takes the agent into the coating film, to thereby exhibitimproved adhesion properties.

Unvulcanized Rubber Compositions and Rubber Moldings

Unvulcanized rubber compositions and rubber moldings can be obtainedfrom epoxidized EPDM, a diene polymer, and a vulcanizing agent.

The EPDM used in the present invention preferably has a number-averagemolecular weight of 2,000-40,000, particularly preferably 3,000-25,000.Moreover, the iodine value of the EPDM is preferably 5-100, particularlypreferably 10-50. The reason is that materials falling within theseranges are readily available.

The oxygen concentration of oxirane of the epoxidized EPDM which is usedin the present invention is preferably 0.1-2.0% by weight, particularlypreferably 0.12-1.8% by weight. Within these ranges, remarkablyexcellent coating properties can be obtained.

The diene polymers which are used in the present invention may behomopolymers, random copolymers, or block copolymers.

When the block copolymers are formed of a vinyl aromatic hydrocarboncompound and a conjugate diene compound, the copolymerization ratio byweight of vinyl aromatic hydrocarbon compound/conjugate diene compoundis preferably 20/80-70/30, particularly preferably 30/70-60/40. Withinthese ranges, unvulcanized rubber compositions or rubber moldingsendowed with excellent coating characteristics can be obtained.

Vulcanizing agents which are used in the present invention includesulfur, metal oxides such as zinc oxide, and organic peroxides. Examplesof organic peroxides include benzoyl peroxide, lauroyl peroxide,bis(t-butylperoxy)-3,3,5-trimethylcyclohexane.

When sulfur is used as the vulcanizing agent, it is preferable to use acure accelerator in an amount of 20-150% by weight with respect to thevulcanizing agent. Examples of the cure accelerator include fatty acidsand their derivatives such as stearic acid, oleic acid, lauric acid, andzinc stearate; and organic compounds such as diphenylguanidine,2-mercaptobenzothiazole, tetramethylthiuram monosulfides, etc. Moreover,inorganic compounds such as zinc flower, zinc carbonate, and magnesiumoxide may also be used. In the present invention, one, two, or more ofthese substances may be used.

The amount of the vulcanizing agent is preferably 0.2-2.5 parts byweight, particularly preferably 0.5-2.0 parts by weight, when the amountin total of the diene polymer and epoxidized EPDM is 100 parts byweight.

The rubber compositions of the present invention may contain, as afiller, plastic fiber, glass fiber, wollastonite, diatomaceous earth,wood powder, natural calcium silicate, asbestos powder, talc, calciumcarbonate, kaolin, celite, etc. The amount of the filler is preferably1-60 parts by weight, particularly preferably 5-40 parts by weight, whenthe amount in total of the diene polymer and epoxidized EPDM is 100parts by weight. In the present invention, one of these fillers may beused singly, or two or more of these fillers may be in combination.

The unvulcanized rubber compositions of the present invention may bemolded through extrusion, compression molding, etc. Extrusion isparticularly preferred. The extrudates may be vulcanized, or in otherwords, treated with heat, to cause crosslinking within the unvulcanizedrubber composition so as to produce rubber moldings.

In the case in which a paint is applied to the unvulcanized rubbercomposition of the present invention, application of the paint may beperformed after vulcanization and before curing. Alternatively,application of the paint may be effected before vulcanization, andvulcanization and curing of the paint may be performed simultaneously.

Paints that may be applied to the unvulcanized rubber compositions ofthe present invention include urethane paints, acrylic resin paints, andpolyester paints. Of these paints, urethane paints are particularlypreferable. Specifically, solvent-free urethane paints which areconstituted by two liquids, i.e., a polyol ingredient that has aterminal OH group and an isocyanate ingredient, are preferred.One-liquid-type paints in which a block-type isocyanate has been blendedwith a polyol ingredient may also be used.

The paints are preferably of the completely solvent-free type. Ifaddition of solvent is sought, a solvent having a boiling point of notlower than 150° C. may be added in an amount of less than 20% by weight.Such an amount will not cause foaming of coating film attributable tothe heat of the vulcanized layer, or deteriorated appearance or reducedfriction resistance which may result from the foaming of coating film.

EXAMPLES

The present invention will next be described by way of examples.However, the present invention is not limited only to the examplesdescribed hereunder, so long as the scope of the invention is notsurpassed. In the following descriptions, "parts" and "%" are all basedon a weight basis.

A. Production of Epoxidized Organic Polymers

Measuring method

(1) Oxygen concentration of oxirane: Measured in accordance withASTM-1652.

(2) Acid value: JIS K-0070

Example 1

In a four-necked flask (capacity: 1 liter) equipped with a stirrer,thermometer, dropping funnel, and reflux condenser were placed 100 g ofa pulverized product of EPDM (iodine number: 10) which had passedthrough a 7.5 mesh sieve (number-average molecular weight of the productas measured by the GPC method: 5,300) and 200 g of ethyl acetate(serving as a solvent), and the contents were stirred and thoroughlymixed so as to disperse EPDM. The mixture was heated to 50° C., and withthe temperature being maintained at 50° C., 12.0 g of 30% ethyl acetatesolution of peracetic acid was added to the flask through the droppingfunnel over approximately 30 minutes so as to cause a reaction. Thereaction mixture was allowed to ripen for 3 hours at the sametemperature.

After completion of ripening, solid matter was recovered by filtration,washed with deionized water in an amount 3 times that of the reactionmixture on a weight basis, to thereby remove acetic acid derived fromperacetic acid. Subsequently, in order to remove water and othersubstances, the reaction mixture was brought to dryness under reducedpressure to obtain 99.0 g of an epoxidized EPDM. The thus-obtainedepoxidized EPDM had an oxirane oxygen concentration of 0.27% and acidvalue of 0.30.

Example 2

In the same type of a four-necked flask as that used in Example 1 wereplaced 100 g of a pelletized product of EPDM (iodine number: 10)available on the market (number-average molecular weight of the productas measured by the GPC method: 5,300) and 200 g of ethyl acetate(serving as a solvent), and the contents were stirred and thoroughlymixed so as to disperse EPDM. The mixture was heated to 50° C., and withthe temperature being maintained at 50° C., 12.0 g of 30% ethyl acetatesolution of peracetic acid was added to the flask through the droppingfunnel over approximately 30 minutes so as to cause a reaction. Thereaction mixture was allowed to ripen for 3 hours at the sametemperature.

After completion of ripening, solid matter was recovered by filtration,washed with deionized water in an amount 3 times that of the reactionmixture on a weight basis, to thereby remove acetic acid derived fromperacetic acid. Subsequently, in order to remove water and othersubstances, the reaction mixture was brought to dryness under reducedpressure to obtain 100.0 g of an epoxidized EPDM. The thus-obtainedepoxidized EPDM had an oxirane oxygen concentration of 0.20% and acidvalue of 0.20.

Example 3

In the same type of a four-necked flask as that used in Example 1 wereplaced 100 g of a pulverized product of EPDM (iodine number: 10) whichhad passed through a 7.5 mesh sieve (number-average molecular weight ofthe product as measured by the GPC method: 5,300), 200 g of ethylacetate (serving as a solvent), and 2.88 g of 90% formic acid, and thecontents were stirred and thoroughly mixed so as to disperse EPDM. Themixture was heated to 50° C., and 5.32 g of aqueous hydrogen peroxidehaving 30% of purity was added to the flask through the dropping funnelover approximately 10 minutes so as to cause a reaction. The reactionmixture was allowed to ripen for approximately 4 hours at the sametemperature.

After completion of ripening, solid matter was recovered by filtration,washed with deionized water in an amount 3 times that of the reactionmixture on a weight basis, to thereby remove carboxylic acid derivedfrom peracid. Subsequently, in order to remove water and othersubstances, the reaction mixture was brought to dryness under reducedpressure to obtain 99.0 g of an epoxidized EPDM. The thus-obtainedepoxidized EPDM had an oxirane oxygen concentration of 0.27% and acidvalue of 0.70.

Example 4

In a four-necked flask (capacity: 3 liters) equipped with a stirrer,thermometer, dropping funnel, and reflux condenser were placed 300 g ofa block-copolymer of SBS (a substance obtained by freezing andpulverizing TR2000 (manufactured by Japan Synthetic Rubber Co., Ltd.))which had passed through a 7.5 mesh sieve and 600 g of hexane, and thecontents were stirred and thoroughly mixed so as to suspend SBS. Themixture was heated to 40° C., and 199 g of 30% ethyl acetate solution ofperacetic acid was continuously added to the flask through the droppingfunnel, the mixture being epoxidized for 3 hours at 40° C. whilestirring.

After completion of reaction, solid matter was recovered from thereaction mixture by filtration and was subsequently washed withdeionized water. The thus-recovered solid matter was subjected toremoval of water and residual solvent therefrom under reduced pressureto obtain 290 g of an epoxidized SBS. The thus-obtained epoxidized SBShad an oxirane oxygen concentration of 3.07% and acid value of 0.55.

Example 5

In the same type of a four-necked flask as that used in Example 4 wereplaced 300 g of pellets of a block-copolymer of SBS (TR2000 manufacturedby Japan Synthetic Rubber Co., Ltd.) and 600 g of hexane, and thecontents were stirred and thoroughly mixed so as to suspend SBS. Themixture was heated to 40° C., and 199 g of 30% ethyl acetate solution ofperacetic acid was continuously added to the flask through the droppingfunnel, the mixture being epoxidized for 3 hours at 40° C. whilestirring.

After completion of reaction, solid matter was recovered from thereaction mixture by filtration and was subsequently washed withdeionized water. The thus-recovered solid matter was subjected toremoval of water and residual solvent therefrom under reduced pressureto obtain 298 g of an epoxidized SBS. The thus-obtained epoxidized SBShad an oxirane oxygen concentration of 1.01% and acid value of 0.23.

Example 6

In the same type of a four-necked flask as that used in Example 4 wereplaced 300 g of NBR (a substance obtained by freezing and pulverizingNipol 1043 (a random copolymer; manufactured by Nippon Zeon Co. Ltd.))which had passed through a 7.5 mesh sieve and 600 g of hexane, and thecontents were stirred and thoroughly mixed so as to suspend NBR. Themixture was heated to 40° C., and 301 g of 30% ethyl acetate solution ofperacetic acid was continuously added to the flask through the droppingfunnel, the mixture being epoxidized for 3 hours at 40° C. whilestirring.

After completion of reaction, solid matter was recovered from thereaction mixture by filtration and was subsequently washed withdeionized water. The thus-recovered solid matter was subjected toremoval of water and residual solvent therefrom under reduced pressureto obtain 275 g of an epoxidized NBR polymer (a random copolymer). Thethus-obtained epoxidized NBR had an oxirane oxygen concentration of4.31% and acid value of 0.34.

Example 7

In the same type of a four-necked flask as that used in Example 4 wereplaced 300 g of a block-copolymer of SIS (a substance obtained byfreezing and pulverizing QUINTAC 3422 (manufactured by Nippon Zeon Co.,Ltd.)) which had passed through a 7.5 mesh sieve and 600 g of hexane,and the contents were stirred and thoroughly mixed so as to suspend SIS.The mixture was heated to 40° C., and 134 g of 30% ethyl acetatesolution of peracetic acid was continuously added to the flask throughthe dropping funnel, the mixture being epoxidized for 3 hours at 40° C.while stirring.

After completion of reaction, solid matter was recovered from thereaction mixture by filtration and was subsequently washed withdeionized water. The thus-recovered solid matter was subjected toremoval of water and residual solvent therefrom under reduced pressureto obtain 290 g of an epoxidized SIS polymer. The thus-obtainedepoxidized SIS had an oxirane oxygen concentration of 1.96% and acidvalue of 0.28.

Example 8

In the same four-necked flask as that used in Example 4 were placed 300g of a polymer of BR (a substance obtained by freezing and pulverizingBR-01 (manufactured by Japan Synthetic Rubber Co., Ltd.)) which hadpassed through a 7.5 mesh sieve and 600 g of hexane, and the contentswere stirred and thoroughly mixed so as to suspend BR. The mixture washeated to 40° C., and 235 g of 30% ethyl acetate solution of peraceticacid was continuously added to the flask through the dropping funnel,the mixture being epoxidized for 3 hours at 40° C. while stirring.

After completion of reaction, solid matter was recovered from thereaction mixture by filtration and was subsequently washed withdeionized water. The thus-recovered solid matter was subjected toremoval of water and residual solvent therefrom under reduced pressureto obtain 281 g of an epoxidized BR polymer. The thus-obtainedepoxidized BR had an oxirane oxygen concentration of 3.38% and acidvalue of 0.30.

Example 9

In a four-necked flask (capacity: 6,000 milliliters) equipped with athermometer, stirrer, and reflux condenser were placed 1,500 g of apulverized product of EPDM (iodine number: 20; number-average molecularweight: 5,300) which had passed through a 7.5 mesh sieve (number-averagemolecular weight of the product as measured by the GPC method: 5,300)and 3,000 g of ethyl acetate (serving as a solvent), and the contentswere stirred and thoroughly mixed so as to disperse EPDM. The mixturewas heated to 50° C., and with the temperature being maintained at 50°C., 450 g of 30% ethyl acetate solution of peracetic acid was added tothe flask through the dropping funnel over approximately 30 minutes soas to cause a reaction. The reaction mixture was allowed to ripen for 3hours at the same temperature. After completion of ripening, solidmatter was recovered by filtration, washed with deionized water in anamount 3 times that of the reaction mixture on a weight basis, tothereby remove acetic acid derived from peracetic acid. Subsequently,the reaction mixture was subjected to removal of the solvent therefromunder reduced pressure to obtain 1,485 g of an epoxidized EPDM. Thethus-obtained epoxidized EPDM had an oxirane oxygen concentration of0.9% and acid value of 0.8.

Comparative Example 1

In the same type of a four-necked flask as that used in Example 1 wereplaced 50 g of pelletized EPDM (iodine number: 10) and 450 g of toluene(serving as a solvent), and the contents were stirred so as to dissolveEPDM. The mixture was heated to 50° C., and 6.0 g of 30% ethyl acetatesolution of peracetic acid was added to the flask through the droppingfunnel over approximately 20 minutes so as to cause a reaction. Thereaction mixture was allowed to ripen for 3 hours at a reactiontemperature of 50° C.

After completion of ripening, the reaction mixture was washed withdeionized water in an amount 3 times that of the reaction mixture on aweight basis, to thereby remove acetic acid derived from peracetic acid.An epoxidized EPDM precipitated during removal of the solvent.Subsequently, in order to remove water and other substances, thereaction mixture was brought to dryness under reduced pressure to obtain89.2 g of an epoxidized EPDM. The thus-obtained epoxidized EPDM had anoxirane oxygen concentration of 0.31% and acid value of 0.30.

B. Thermoplastic Resin Compositions

Examples 10 and 11

Polypropylene (NOBLEN H-501 manufactured by Sumitomo Chemical Co.,Ltd.), an epoxidized EPDM which had been obtained in accordance withExample 9, an acid anhydride (Methylhimich anhydride manufactured byHitachi Chemical Co., Ltd.), and triphenylphosphine were mixed such thatall the substances except triphenylphosphine were mixed at proportions(parts by weight) indicated in Table 1 while triphenylphosphine wasmixed at a proportion of 1 part by weight based on 100 parts by weightof the epoxidized EPDM. The resulting mixtures were melted and kneadedwith an extruder (at a temperature of 210° C.). The thus-obtained resincompositions were cooled and then pelletized. The pellets were pressedinto test pieces for use in a mechanical strength test. The test resultsare shown in Table 1. As seen from Table 1, the thermoplastic resincompositions of the present invention can improve impact strengthwithout decreasing tensile strength.

                  TABLE 1                                                         ______________________________________                                                                 Comparative                                                                             Comparative                                  Example 10   Example 11   Sample 1      Sample 2                            ______________________________________                                        Polypropylene                                                                          100       100       100     100                                        Epoxidized            40          20       30                                 EPDM                                                                          Acid anhydride          4         2                             3                                                 Impact                  6         5                                                     2              2                strength                                                                      (kg · cm/cm)                                                         Tensile              410           430           250           350                                                strength                                  (kgf/cm)                                                                      Hardness             102           100             75                       ______________________________________                                                                             95                                   

Measuring Methods

(1) Izod impact strength: JIS K6758 (23° C.)

(2) Tensile strength: JIS K6755 (breaking strength)

(3) Hardness: JIS K6758 (Rockwell R)

C. Primer Compositions

Example 12

Through use of the epoxidized EPDMs of Examples 1 and 2 and products ofchlorination of a polypropylene modified with maleic anhydride(abbreviated as chlorinated modified PP in Table 2) of SynthesisExamples 1 and 2 described below, samples 1 to 3 and comparative samples1 and 2 of a primer composition were prepared in accordance with Table2.

The primer compositions were applied onto respective backing materialsof polypropylene (TX-1180 manufactured by Mitsubishi Chemical Corp.)with an air spray gun so as to form a film having a thickness of 10 μmthereon. The thus-coated backing materials were allowed to stand for 10minutes at room temperature. Subsequently, a urethane paint (LETAN PG2KM CLEAR manufactured by Kansai Paint Co., Ltd.) was applied in the samemanner onto the coated backing materials so as to attain a filmthickness of 25 μm, followed by drying for 20 minutes at 120° C.

Physical properties of the thus-formed films and storage stability ofthe prepared paints were evaluated. Evaluation results are shown inTable 2.

Synthesis Example 1

500 g of isotactic polypropylene (melt viscosity at 180° C.:approximately 2,500 cps) was placed in a three-necked flask equippedwith a stirrer, dropping funnel, and a condenser tube for refluxing amonomer. The flask was placed in an oil bath which was maintained at aconstant temperature of 180° C. to thereby melt isotactic polypropylenecompletely. Subsequently, the interior atmosphere of the flask wasreplaced with nitrogen for approximately 10 minutes. Then, 20 g ofmaleic anhydride was added to the flask over approximately 5 minutes.Next, 2 g of di-tert-butyl peroxide was dissolved in 10 ml of heptane.The resulting solution was added to the flask through the droppingfunnel over approximately 30 minutes. With the interior temperature ofthe flask being maintained at 180° C., reaction was continued forapproximately another 1 hour. Subsequently, while the interior pressureof the flask was being reduced through use of an aspirator, unreactedmaleic anhydride was removed over approximately 30 minutes. Thethus-obtained product had a saponification value of 25.

To 300 g of this product was added 5 liters of carbon tetrachloride,followed by dissolution at 110° C. under a chlorine gas pressure of 2kg/cm². Subsequently, while the solution was being irradiated withultraviolet rays, gaseous chlorine was bubbled thereinto from the bottomportion of the reactor until the degree of chlorination became 25% byweight. After completion of reaction, carbon tetrachloride (serving as asolvent) was removed with an evaporator, followed by replacement withtoluene, thereby obtaining 20% by weight toluene solution of a productof chlorination of a polypropylene modified with a maleic anhydride. Theproduct of chlorination (solid matter) had a saponification value of 24.

Synthesis Example 2

A polypropylene modified with a maleic anhydride having a saponificationvalue of 36 was obtained from 500 g of isotactic polypropylene used inSynthesis Example 1 through use of 30 g of maleic anhydride and 2 g ofdi-tert-butyl peroxide in a manner similar to that of SynthesisExample 1. Subsequently, a chlorination reaction was performed inaccordance with Synthesis Example 1, thereby obtaining 20% by weighttoluene solution of a product of chlorination (degree of chlorination:25% by weight) of a polypropylene modified with a maleic anhydride. Theproduct of chlorination (solid matter) had a saponification value of 34.

Results

As shown in Table 2, as compared with comparative samples 1 and 2representing a comparative primer composition, significantly improvedproperties were exhibited by samples 1 to 3 representing a primercomposition of the present invention which was prepared through use ofan epoxidized EPDM, i.e., an epoxidized organic polymer produced by theprocess of the present invention.

                  TABLE 2                                                         ______________________________________                                                                         Com-  Com-                                                               parative parative                                   Sample Sample Sample Sample Sample                                            1  2 3   1  2                                                               ______________________________________                                        Epoxidized                                                                              100      100                   100                                    EPDM                                                                          (Example 1:                                                                   parts)                                                                        Epoxidized                              100         100                       EPDM                                                                          (Example 2:                                                                   parts)                                                                        Chlorinated            66         60                                          modified PP                                                                   (Synthesis                                                                    Example 1:                                                                    parts)                                                                        Chlorinated                                  55         30                                                           40                                     modified PP                                                                   (Synthesis                                                                    Example 2:                                                                    parts)                                                                        Degree of              25         25       25         25            25                                                chlorination of                       chlorinated                                                                   modified PP                                                                   (% by weight)                                                                 Physical                                                                      properties                                                                    of film                                                                       Adhesion      25/25      25/25     25/25      25/25         0/25                                                      Adhesion      25/25      25/25                                                  25/25      25/25         0/25       against                                                                       water                                                                         Film            ∘          ∘         .smallcircl                                             e.         ∘                                                          ∘                      stickiness                                                                    Storage                ∘          ∘                                                          ∘    Crystal-                                                     ∘                          stability of                                                line                                                      paint                                                                        blob-                                                                                              bing            ______________________________________                                    

Measuring Methods

(1) Adhesion: The film surface of each test piece was cut crisscrossedat 2 mm intervals so as to form 25 squares. Subsequently, adhesive tapewas stuck on the film surface and was then peeled off upward at astroke. Unremoved squares were counted and represented as a ratio to thetotal number of squares (25) for evaluation.

(2) Adhesion against water: Test pieces were immersed in warm waterhaving a temperature of 40° C. for 240 hours. Subsequently, the testpieces underwent measurement similar to that in (1) "Adhesion" above tothereby evaluate their adhesion against water.

(3) Film stickiness: After preparation of test pieces, they weretactually tested for stickiness with a finger to thereby evaluate filmstickiness thereof. The absence of stickiness was indicated by "O," andthe presence of stickiness was indicated by "X."

(4) Storage stability: Compositions were allowed to stand for 14 days at60° C. Subsequently, they were visually checked for crystallineblobbing. The absence of crystalline blobbing was indicated by "O."

(5) Bonding force: Each of vulcanized samples was cut into two pieces,each measuring 5 mm (width)×100 mm (length)×1.5 mm (thickness). Thethus-obtained two pieces were bonded together with a bonding agent (theinstantaneous bonding agent "ZERO TIME" manufactured by CemendineCorporation Ltd.) such that smooth urethane surfaces thereof faced eachother. The bonding force of the thus-bonded two pieces was measuredthrough use of a TENSILON type tensile tester manufactured by ShimazuCorporation.

D. Unvulcanized Rubber Compositions

Example 13

Through use of an epoxidized EPDM which had been obtained in accordancewith Example 9, unvulcanized rubber compositions were manufactured inaccordance with formulations shown in Table 3. Each of the thus-obtainedunvulcanized rubber compositions was extruded to obtain extrudates. Theextrudates were vulcanized and then coated with a urethane paintobtained below in Reference Example. The thus-coated extrudates weretested for bonding force and state of separation. The results are shownin Table 3.

Reference Example

Preparation of Urethane Paints

To a urethane resin component which had been obtained from two liquidsconsisting of 100 parts by weight of an polyol component (PU-5106manufactured by Toa Gosei Co., Ltd.) having a terminal OH group in themolecule and 100 parts by weight of an isocyanate component (PU-1300manufactured by Toa Gosei Co., Ltd.) were added 10 parts by weight ofdimethyl silicone oil (TSF451-10M manufactured by Toshiba SiliconeCorporation Ltd.; 100,000 cps) serving as a liquid lubricant, 10 partsby weight of fluorine-contained resin powder (L180J manufactured byAsahi Glass Co., Ltd.; grain size: 20-100 μm) serving as a solidlubricant, 5 parts by weight of molybdenum disulfide, 10 parts by weightof grains of nylon (average grain size: 50 μm), and 5 parts by weight ofgrins of polyethylene (average grain size: 50 μm), to thereby prepare asolvent-free urethane paint.

Results

A comparative composition had a bonding force of 0.3 kg/cm or less, andits smooth urethane layer which had been formed through application of aurethane paint exhibited interface separation. It is not shown in Table3, but when an epoxidized EPDM was added in an amount of 80 parts byweight or more, it reacted with a cure accelerator, resulting inslowdown of vulcanization and an approximately 10% reduction of tearingstrength.

                  TABLE 3                                                         ______________________________________                                                    Com-                                                                            parative   Sample  Sample  Sample  Sample                         (Parts by weight)            sample        1       2       3                ______________________________________                                                                                 4                                    Epoxidized EPDM                                                                           --       20      40    60    70                                     SBR                                75        80       60      40                                                     30                                     EPDM                               25         --       --       -- --       Zinc flower                            4                                        Stearic acid                                          2                       CaO                                                   5                       FEF carbon                                           65                       Calcium bicarbonate                                  30                       Paraffin oil                                         30                       Sulfur                                               1.5                      Cure accelerator                                     4.0                    Bonding force (kg/cm)                                                                     0.25     1.2     1.2   1.2   1.2                                    State of separation          Interface     Base    Base    Base    Base                                     separation    material  material                                                       material  material                                                                   separa-  separa-  separa-                                               separa-                                                                             tion    tion    tion                                                   tion                                 ______________________________________                                    

Measuring Method

State of separation: The state of separation was visually observed.After separation, when only a film adhered to a test piece, it wasjudged as interface separation; when a base material adhered to a testpiece, it was judged as base material separation.

Industrial Applicability

1. The process of the present invention for producing an epoxidizedorganic polymer exerts specially advantageous effects as described belowand therefore, its industrial utility is quite remarkable. That is,according to the process of the present invention, an organic polymer tobe epoxidized, such as a resin or rubber polymer, which has double bondsin the molecule and which is solid at normal ambient temperature can bereadily epoxidized in an unhomogeneous system by simply dispersing orsuspending the polymer in a solvent, with the necessity of dissolvingthe polymer being eliminated. Also, according to the process of thepresent invention, the organic polymer to be epoxidized is dissolved orsuspended in a solvent for epoxidization, and the produced epoxidizedorganic polymer can be recovered in a solid form. Therefore, thepost-treatment operation is simple, workability is improved, and inaddition, the product can be obtained at a high recovery ratio.

2. The thermoplastic resin composition of the present invention hasgreatly improved mechanical strength as compared with its constituentstarting thermoplastic resin.

3. The primer composition of the present invention exhibits excellentstorage stability and remarkable adhesion to moldings and materials ofpolyolefin such as polypropylene as well as to topcoats. Moreover, thecomposition also exhibits excellent adhesion even when moldings arecontaminated with mold-releasing agents.

4. According to the present invention, there is provided an unvulcanizedrubber composition comprising a diene polymer and an epoxidized EPDM,rubber moldings formed of the composition, and a process for theproduction of the rubber moldings. Since the unvulcanized rubbercomposition of the present invention exhibits excellent coating ability,rubber moldings having complicated shapes can be produced with ease.

What is claimed is:
 1. A thermoplastic resin composition comprising athermoplastic resin, an epoxidized EPDM, and an organic compound havinga functional group that reacts with an epoxy group, wherein theepoxidized EPDM is produced by a process comprising dispersing orsuspending an EPDM having an iodine value of 5-100, which is a rawmaterial of the epoxidized EPDM, in an organic solvent and epoxidizingthe EPDM with a peroxide so as to have an oxygen concentration inoxirane of 0.1-2.0% by weight.
 2. The thermoplastic resin compositionaccording to claim 1, wherein the thermoplastic resin is polyolefin. 3.The thermoplastic resin composition according to claim 2, wherein thepolyolefin is polypropylene.
 4. The thermoplastic resin compositionaccording to claim 1, wherein the epoxidized EPDM is used in an amountof 10-60 parts by weight with respect to 100 parts by weight of thethermoplastic resin, and the organic compound having a functional groupthat reacts with an epoxy group is incorporated, into epoxidized EPDM,in an amount of 0.5-2 equivalent weights of the oxygen concentration ofoxirane of the epoxidized EPDM.
 5. The thermoplastic resin compositionaccording to claim 1, wherein the organic compound having a functionalgroup that reacts with an epoxy group is an acid anhydride.
 6. Thethermoplastic resin composition according to claim 4, wherein thepolyolefin is polypropylene and the organic compound having a functionalgroup that reacts with an epoxy group is an acid anhydride.
 7. Athermoplastic resin composition consisting essentially of athermoplastic polyolefin resin, an epoxidized EPDM, and an organic acidanhydride compound having a functional group that reacts with an epoxygroup, wherein said epoxidized EPDM contains 50% to 80% of double bondsthat are epoxidized and has an 0.1-2.0% by weight oxygen concentrationof oxirane, and wherein the epoxidized EPDM is used in an amount of10-60 parts by weight with respect to 100 parts by weight of athermoplastic polyolefin resin, and the organic acid anhydride compoundhaving a functional group that reacts with an epoxy group isincorporated, into the epoxidized EPDM, in an amount of 0.5-2 equivalentweights of the oxygen concentration of oxirane of the epoxidized EPDM.8. The thermoplastic resin composition according to claim 7, wherein theorganic acid anhydride compound having a functional group that reactswith an epoxy group is maleic anhydride.
 9. A thermoplastic resincomposition comprising a thermoplastic polyolefin resin, an epoxidizedEPDM, and an acid anhydride having a functional group that reacts withan epoxy group, wherein the epoxidized EPDM is produced by a processcomprising dispersing or suspending an EPDM having an iodine value of5-100, which is a raw material of the epoxidized EPDM, in an organicsolvent and epoxidizing the EPDM with a peroxide so as to have an oxygenconcentration in oxirane of 0.1-2.0% by weight, and wherein theepoxidized EPDM is used in an amount of 10-60 parts by weight withrespect to 100 parts by weight of the thermoplastic resin, and theorganic compound having a functional group that reacts with an epoxygroup is incorporated, into epoxidized EPDM, in an amount of 0.5-2equivalent weights of the oxygen concentration of oxirane of theepoxidized EPDM.
 10. The thermoplastic resin composition according toclaim 9, wherein the polyolefin is polypropylene.
 11. The thermoplasticresin composition according to claim 9, wherein the polyolefin ispolypropylene and the organic compound having a functional group thatreacts with an epoxy group is maleic anhydride.